diff --git a/railties/lib/rails/application.rb b/railties/lib/rails/application.rb
index ed7bca4e3ca8f78e4a3a2e973375c44da938fe76..93524ae1479232fee88636a81e8a40962bc72f82 100644
--- a/railties/lib/rails/application.rb
+++ b/railties/lib/rails/application.rb
@@ -497,6 +497,15 @@ def migration_railties # :nodoc:
       ordered_railties.flatten - [self]
     end
 
+    # Eager loads the application code.
+    def eager_load!
+      if Rails.autoloaders.zeitwerk_enabled?
+        Rails.autoloaders.each(&:eager_load)
+      else
+        super
+      end
+    end
+
   protected
     alias :build_middleware_stack :app
 
diff --git a/railties/lib/rails/engine.rb b/railties/lib/rails/engine.rb
index d7dc9869b0c9d44399095f59e61c5454b8f47394..93940e5a088c4be6cbc3d3aa62ed339de2d58fc2 100644
--- a/railties/lib/rails/engine.rb
+++ b/railties/lib/rails/engine.rb
@@ -471,7 +471,8 @@ def load_generators(app = self)
     end
 
     def eager_load!
-      # Already done by Zeitwerk::Loader.eager_load_all in the finisher.
+      # Already done by Zeitwerk::Loader.eager_load_all. We need this guard to
+      # easily provide a compatible API for both zeitwerk and classic modes.
       return if Rails.autoloaders.zeitwerk_enabled?
 
       config.eager_load_paths.each do |load_path|
diff --git a/railties/test/application/zeitwerk_integration_test.rb b/railties/test/application/zeitwerk_integration_test.rb
index ab8dbe64d34dc2991e3dc4db07fe39157d53a00f..af230f73c386cc7950735c7218735df9482a1cf6 100644
--- a/railties/test/application/zeitwerk_integration_test.rb
+++ b/railties/test/application/zeitwerk_integration_test.rb
@@ -192,6 +192,26 @@ def user.to_path; "user"; end
     assert $zeitwerk_integration_test_post
   end
 
+  test "eager loading loads the application code if invoked manually too (regression test)" do
+    $zeitwerk_integration_test_user = false
+    $zeitwerk_integration_test_post = false
+
+    app_file "app/models/user.rb", "class User; end; $zeitwerk_integration_test_user = true"
+    app_file "app/models/post.rb", "class Post; end; $zeitwerk_integration_test_post = true"
+
+    boot
+
+    # Preconditions.
+    assert !$zeitwerk_integration_test_user
+    assert !$zeitwerk_integration_test_post
+
+    Rails.application.eager_load!
+
+    # Postconditions.
+    assert $zeitwerk_integration_test_user
+    assert $zeitwerk_integration_test_post
+  end
+
   test "reloading is enabled if config.cache_classes is false" do
     boot